Field of the Invention
The present invention relates to a method for rehabilitating a pipe using segments each comprising an inner surface plate constituting an inner circumferential surface, and side plates and end plates provided upright on peripheral edges of the inner surface plate, wherein the inner surface plate, the side plates, and the end plates are formed integrally from a plastic material and the segments are linked in the circumferential direction and in the pipe-length direction to construct a rehabilitation pipe inside an existing pipe.
Description of the Related Art
In cases in which an existing pipe such as a large-diameter sewage pipe buried underground has deteriorated through aging, a pipe lining method has been proposed and practiced in which a lining is provided to the inner circumferential surface thereof to repair the pipe without excavating it from the ground. In this pipe lining method, the segments are linked in the circumferential direction to assemble pipe units, which are then linked in the pipe-length direction using a linking member to construct a rehabilitation pipe inside an existing pipe. After assembling a rehabilitation pipe inside the existing pipe, grout or another filler is injected into a space between the existing pipe and the rehabilitation pipe and hardened to construct a composite pipe.
When the filler is injected between the existing pipe and the rehabilitation pipe, the rehabilitation pipe floats on the filler because the rehabilitation pipe is made of a plastic material having a specific gravity lower than the filler. To prevent the rehabilitation pipe from floating, a spacer as disclosed in JP 2005-265070 A1 is inserted in a gap between the rehabilitation pipe and the existing pipe every time the rehabilitation pipe is assembled a predetermined length (for example, one meter). This ensures that the rehabilitation pipe is pressed downward and prevented from floating on the filler.
In such a method, the spacer is pushed with a tension between the rehabilitation pipe and the existing pipe, so that, if the spacer is inappropriately inserted, it falls down or deviates from an appropriate position, causing the rehabilitation pipe to be maladjusted. Installing the spacer appropriately at a plurality of locations disadvantageously increases work steps.
An object of the present invention is therefore to provide a method for rehabilitating an existing pipe being capable of preventing a position adjusting spacer from falling down or deviating from an appropriate position.